Static protein adsorption, ultrafiltration behavior and cleanability of hydrophilized polysulfone membranes

Abstract

A systematic study on the in¯uence of incrementally increased hydrophilicity of UF membranes made from chemically modi®ed polysulfone on static protein adsorption, protein ultra®ltration performance and cleanability was performed. Hydrophilicity was imparted to the polymeric backbone either by carboxylation or sulfonation. Membranes with 100% retention towards sulfhydryl modi®ed bovine serum albumin (cys-BSA) were made by the phase inversion process from unmodi®ed polysulfone, ®ve carboxylated polysulfones (degrees of carboxylation ranging from 0.26 to 1.74) and two sulfonated polysulfones (degrees of sulfonation of 0.24 and 0.58). 1000 ppm aqueous solutions of cys-BSA at pH values 3, 4.8 and 9 were used in KCl medium at either low or high concentration. Static adsorption, ultra®ltration (UF)¯ux reduction and protein binding strength were lower at pH 3 than at pH 9 but reached an expected maximum at the protein's isoelectric point at pH 4.8. Hydrophilized polysulfone membranes show less static adsorption and lower UF¯ux reduction than hydrophobic unmodi®ed membranes. In all experiments we found that the higher the degree of carboxylation or sulfonation, the greater this effect. High ionic strengths reduced these advantages at pH values above or below the IEP but had a positive effect at the IEP. #

Polyamide thin-film composite membranes based on carboxylated polysulfone microporous support membranes for forward osmosis

“…Chemical modifications, such as amination [20][21][22], sulfonation [23][24][25], and carboxylation [26][27][28], have been used to impart hydrophilicity to hydrophobic PSF.…”

“…Previously, Guiver et al [26] reported the carboxylation of polysulfone (PSF) via a direct lithiation method followed by carbon dioxide and acid treatment. The chemical [26,33,34] and separation properties of these materials as RO and UF membranes [27,28] have been reported in the literature. Here, CPSFs were prepared as new supporting membrane materials for FO membranes.…”

Polyethersulfone Hollow Fiber Membranes for Hemodialysis

“…The hydrophilic/hydrophobic character of membrane material plays a relatively important role in the interaction between protein and membrane. Since hydrophilic surface preferentially adsorbs water rather than solutes, many researchers have followed the idea of increasing the hydrophilicity of a membrane material with the goal of reducing protein fouling and/or protein adsorption (Mockel et al, 1999). Herein, the surfaces of the PES and some typical modified PES membranes (Copolymer of poly (acrylonitrile-co-acrylic acid), PAN-AA, modified PES membranes with the ratios of the copolymer to PES of 0/16, 0.4/16 and 0.6/16, respectively; and BSA grafted membranes following the copolymer/PES blended membranes) were studied in relation to the adsorption of BSA and FNG in vitro, data are shown in Fig.…”

Study of Polysulfone and Polyacrylic Acid (PSF/PAA) Membranes Morphology by Kinetic Method and Scanning Electronic Microscopy

“…However, the hydrophobic behaviour prevents its use in several areas such as in water treatment. In order to overcome this drawback, some researchers have proposed the incorporation of hydrophilic groups, to increase the polymer hydrophilicity which improves the membrane water-permeability and reduces membranefouling [1,2].…”

“…Membranes were prepared by (i) substitution with functionalized groups, (ii) by polymer graft modification or (iii) by surface modification of prefabricated membranes [2][3][4][5][6][7][8][9].…”